Effect of Melamine on the Oxygen Reduction Reaction in the n(111)-(111) Series of Pt3Co

Abstract

Abstract Enhancement of the oxygen reduction reaction (ORR) activity is an important subject for the development of fuel cells. In this study, we prepared the n(111)-(111) series of Pt3Co single crystal electrodes using an induction heating furnace and investigated the ORR in 0.1 M HClO4 using the rotation disk electrode (RDE). The specific activity of the ORR (j k) increased monotonously with increasing terrace width n on the n(111)-(111) series of Pt3Co, showing the highest activity on Pt3Co(111). The value of j k of Pt3Co(111) was 59-fold higher than that of Pt(111) at 0.95 V(RHE). This trend was different from those of the same series of Pt, Pt3Co, and Pt3Ni reported previously. Furthermore, the ORR activity was improved on all electrodes by adding melamine to the electrolytic solution. Melamine was preferentially adsorbed at the terrace edge. Pt3Co(553) n = 5 showed the highest activity. The values of j k at 0.95 V(RHE) were 23- and 3.3-fold higher than those of Pt(553) n = 5 and Pt3Co(553) n = 5 without melamine modification, respectively. The durability of Pt3Co(553) n = 5 with melamine was improved 8.0-fold. Graphical Abstract